Following acute
myocardial infarction, fragments of human
cardiac myosin can be detected in plasma by means of
monoclonal antibodies to
myosin heavy chains from the left human ventricle. The cumulative amounts of
myosin released during the first 9 post-
infarction days are proportional to the size of the
infarct (
Tao Ming et al., in the press). The purpose of our study was to evaluate the effectiveness of a fibrinolytic treatment administered in the acute phase of
myocardial infarction by measuring in the plasma, the circulating fragments of human
cardiac myosin. Three groups of patients with acute
myocardial infarction were investigated: 13 patients (group A) received a conventional treatment; 8 patients (group B) were treated with intravenous
streptokinase without success, i.e. with persistence of the
coronary occlusion; 9 patients (group C) were successfully treated with intravenous
streptokinase, resulting in recanalization of the coronary artery. We found that the cumulative amount of
myosin released during the first 9 post-
infarction days was significantly lower in patients successfully treated with
streptokinase [group C: (3.8 +/- 2.3) 10(3) ng/ml/day]. There was no difference in cumulative release of
myosin between control patients [group A: (7.0 +/- 3.3) 10(3) ng/ml/day] and patients with unsuccessful fibrinolytic treatment [group B: (10.0 +/- 4.1) 10(3) ng/ml/day]. These results were unrelated to the localisation of the
infarct. It is concluded that measuring the cumulative amounts of
myosin released is a means of evaluating the effectiveness of
fibrinolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)